A Reddit user has found two encrypted notes and a few geographic coordinates in an old travel book. Can a reader find out what these messages mean?
Anamorphics are puzzles based on a kind of secret writing. Here are a few examples, some of which are over 100 years old.
Blog reader Magnus Ekhall has taken a trip to the Rök runestone, a famous cryptologic sight in Sweden. Here are his report and a few photographs he took.
In 1999 cryptographer Ron Rivest published an encrypted text that was designed to take 35 years to break. Apparently, it has now been solved.